+1
I don't think any game dynamic leading to tanking as a strong strategy should compete against smart training + smart tactics (that demand much more effort) in effectiveness is anywhere near good.
Tanking is effective but bored. So an average user probably wants to succeed he look his top division an sees this two strategies working, he can go the hard way while seeing others go the easy one and be more effective than him (hard way needs learning, time and many trial and mistake) and decide to quit. Its just an online game, they are plenty of them to try. Or he can simply go tank, quit while bored, or succeed and then, he will have to face again those two options: hard way require skills he hasn't developed and taking will be more bored than the first time. Probably quit.
Many managers will simply quit after discovering there is no fun not so hard alternative for development after a few months. Then, quit.
This is not everybody story. Will it be the one of 65% new users? That can be a disaster when adding old users quits. Perhaps, for similar reasons.